The Arboretum is looking a little sparse these days as autumn’s colorful foliage has given way to the bare branches of early winter. A limited color palette of grays and browns now dominates, so it was particularly delightful to come across two splashes of bright purple on a recent hike to the summit of Bussey Hill.
The first was the aptly named purple beautyberry (Callicarpa dichotoma), a deciduous shrub native to eastern Asia (China, Japan, Korea, and Vietnam). This species grows 3 to 8 feet tall with many slender, arching branches. It bears clusters of small pinkish flowers in mid to late summer, but it’s the fruit that follows that provides the real show. The large specimen (145-23*A) on Bussey Hill, near the entrance to the Explorers Garden’s Chinese Path, is loaded with thousands of the small (about 1/8 to 1/6 inch diameter) bright pinkish purple fruits. (Though called “berry” in the common name, the fruit are actually drupes.) This spectacular display starts in early autumn but is especially noticeable once the leaves have dropped. Often the fruit has been eaten by birds or has discolored or dropped by late autumn, but this year, perhaps thanks to the stretch of mild temperatures we’ve been enjoying, the show seems to be extended on our beautyberries.
The other burst of purple was more surprising: a Korean rhododendron (Rhododendron mucronulatum) in nearly full bloom at the top of the hill. This small deciduous rhododendron is normally one of the first Rhododendron (azaleas and rhododendrons) species to bloom in early spring at the Arboretum, producing a welcome, though not densely floriferous, display of small pinkish purple flowers. This spring-y color show seemed even more out of place because the Korean rhododendron specimen (271-74*A) in bloom was right next to a mass of Japanese spirea (Spiraea japonica ‘Atrosanguinea’, accession 1033-66) still displaying yellow, orange, and red fall foliage. It’s not terribly unusual to see a few fall flowers on certain spring-blooming woody plants (examples include forsythias, crabapples, ornamental cherries, and some rhododendrons such as the ‘P.J.M’ types); this fall bloom usually occurs when an autumn cold spell is followed by a stretch of warmer weather. Typically only a small percent of flower buds open in fall so the spring show is little diminished, but this Korean rhododendron appears to have spent most of its flower buds this autumn, meaning it won’t provide much spring bloom next year. But I and other visitors certainly appreciated seeing its unexpected blossoms before winter settles in.
– Nancy Rose, editor of Arnoldia